In a large pot on medium heat, cook onions and carrots until soft and translucent. Add garlic and spices and cook, stirring constantly for about 1 minute. Add chickpeas, tomatoes, vinegar, soy sauce and stock. Bring to a boil, reduce heat and simmer for 20 minutes or until carrots are tender.  In a blender, blend half of the soup with tahini until smooth. Return to pot, heat through, add salt and pepper if need. Garnish with parsley.